1. Field of the Invention
The present invention relates to an optical disk drive, and more particularly, to an optical disk drive including a tray, which slidably loads into and unloads from a main body of the optical disk drive.
2. Description of the Related Art
In general, an optical disk drive is a device for recording/reading data by irradiating light to a recording surface of a rotating optical disk.
FIG. 1 illustrates a conventional optical disk drive, and FIG. 2 is a cross-sectional view along line I-I′ of FIG. 1.
In FIGS. 1 and 2, the conventional optical disk drive includes a main frame 10, a tray 20, and a deck portion 30.
The main frame 10 includes a pair of rails 11 for guiding a sliding operation of the tray 20. The rails 11 are installed integrally with the main frame 10. Also, the main frame 10 includes a loading motor 13, which provides driving power to slide the tray 20, and a pinion gear 14, which is operated by the loading motor 13.
The tray 20 includes a mounting surface 21, on which a disk (not shown) is mounted, and a rack gear 22, which is connected to the pinion gear 14, on a lower surface of the tray 20.
A deck portion 30 includes a spindle motor 31 which rotates the disk, and an optical pickup 32 accessing the disk by sliding in a radial direction of the disk. The deck portion 30 is installed on the main frame 10, and rises toward the lower surface of the disk when the tray 20 is loaded by the operation of a cam (not shown), which is connected to the loading motor 13, and descends when the tray is unloaded.
When the disk is to be loaded, the disk is mounted on the mounting surface 21 of the tray 20, and the loading motor 13 is rotated. Then, the pinion gear 14 rotates, and the rotary force of the pinion gear 14 is transmitted to the rack gear 22 to slide the tray 20. While the tray 20 is loading, the deck portion 30 rises, and when the loading of the tray 20 is completed, the disk is mounted on a turntable 33, which is coupled to a rotary shaft of the spindle motor 31. The unloading operation of the disk is made by performing the above processes inversely.
The tray 20 is guided by rails 11 while being loaded into the main body 10. As shown in FIG. 2, recesses 23 are disposed on both edges of the tray 20 to be coupled to the rails 11. In order to slide the tray 20 along the rails 11, there should be a tolerance between each rail 11 and each recess 23. Thus, a width (W1) of the recess 23 is larger than the width (W2) of the rail 11, and a distance (W3) between the recesses 23 is larger than the distance (W4) between the rails 11.
The distances between the recesses 23 and the rails 11 should be controlled accurately for sliding the tray 20 smoothly. Otherwise, the tray 20 may vibrate or slant toward one side in sliding operation, thus increasing the loads of the loading motor 14. Also, since the distance between the pinion gear 14 and the rack gear 22 increases due to the tolerances between the recesses 23 and the rails 11, the pinion gear 14 and the rack gear 22 may not engage smoothly.
The main frame and the tray are generally fabricated in an injection molding method for mass production, however, widths W1, W2, W3, and W4 may vary depending on the molding conditions. Therefore, it is difficult to control the distances precisely.